

ABSTRACT

The machine includes two half-frames vertically arranged side by side, with two parallel vertical shafts respectively supported by the two half-frames. A separate turret is pivotally supported around each of the shafts, each turret having a cutting head which can rotate around a horizontal axis and which is equipped with tools for excavating. The two half-frames are slidably movable horizontally in relation to one another, with a control member connected between the half-frames for controlling the relative movement, the two half-frames being selectively positionable on the gallery floor by said relative movement, one half-frame being movable while the other half-frame remains fixed in position.



